Three Mountains

 
Prerequisite(s): Cleave, Power Attack, Improved Bullrush, Weapon Focus (Heavy Mace, Morningstar or Greatclub), Str 13+.
 
Benefit: If you strike the same creature twice in the same round with your heavy mace, morningstar, or greatclub, it must make a Fortitude saving throw (DC 10 + 1/2 your character level + your Str modifier) or be nauseated by the pain for 1 round.
 
Source: Complete Warrior